"Arctic Sentry underscores the alliance's commitment to safeguard its members and maintain stability in one of the world's most strategically significant and environmentally challenging areas," US General Alexus Grynkewich, NATO's Supreme Allied Commander Europe, said in a statement.

NATO said the "multi-domain activity" would initially pull together undertakings already being carried out by alliance members in the region such as upcoming exercises by Norway and Denmark.

It remained unclear whether the new mission would involve more military capabilities being sent to the region.

Trump's threats against Greenland last month -- which he based on an alleged threat by Russia and China in the Arctic -- plunged the transatlantic alliance into its deepest crisis in years.

The unpredictable US leader backed off his vow to take control of Denmark's autonomous Arctic territory after saying he had struck a "framework" deal with NATO chief Mark Rutte to ensure greater American influence.

"The two leaders agreed that NATO should collectively take more responsibility for the defence of the region considering Russia's military activity and China's growing interest there," NATO said in a statement.

The launch of the Arctic Sentry mission comes after NATO last year launched emergency missions in the Baltic Sea and along its eastern flank to try to shore up protection against Moscow.